In the previous post, I talked very briefly about a one instruction set computer. I didn’t go into details because I hadn’t had a chance to play with one yet. Well, I’ve played with it, and it isn’t as difficult as I was making it.
The one command I’m playing with is called subleq. That short for, “subtract and branch if less than or equal to 0.” Don’t worry if this doesn’t make sense yet; I’ll explain in painful detail in future posts.
Symbiosis between animals and bacteria is very common. In some cases, animals will not develop fully without their microscopic partners—sometimes, they can’t even reproduce.
Here’s a paper on the bobtail squid, and the light producing organ that doesn’t develop fully without the correct strain of bioluminescent bacteria.
Many life forms live in partnership with other organisms. The cooperative relationship is called symbiosis. Sometimes, one of the cooperating creatures lives inside of the other, even inside the cells. When one creature lives inside of another one that it cooperates with, it is called endosymbiosis. Today, we take a look at a few examples.
Here’s a review of endosymbiosis, with many examples.
Here’s a couple of articles about Salamanders and algae—the only known vertebrate case of endosymbiosis where the symbionts live within the vertebrate cells.
Today, we talk about another fast moving plant, called mimosa pudica, AKA. Shame plant, shy plant, touch me not, or the tickle me plant. This little plant will curl up its leaves when they are touched.
Here’s a video that shows the tickle me plant in action.
We move and eat via our nerves and muscles, but there are some plants that have no nerves and no muscles, and yet they still move and eat. Today, we talk about the Venus flytrap, and how it why it does what it does.
Special thanks to @StoneyJehker34, for the question and the topic.
Here’s a video showing the Venus flytrap in action.
It seems that most of our DNA is dormant. It doesn’t encode for protein production. Some of this supposedly dormant DNA has recently been shown to have important functionality, but there still seems to be much more information present than is used.
Here’s an article on the debate over how much of our DNA is functional.
Evolution creates designs in ways that human engineers probably wouldn’t. We probably wouldn’t use eyes to grow a brain, or pseudo-gill-slits to grow a face, but evolution does.
Sometimes, evolution can take it back. Many cave dwelling animals have lost their eyes. Theories as to why this happen range from genetic drift, to mutations that improve other senses interfering with the proper development of eyes, to the energy cost of growing and maintaining vision. I suspect that it has to do with how easily injured eyes are when they don’t work. I’ve never seen that brought up by scientists; maybe you have to go blind to get it.
Here’s an article on the kiwi bird and how it may be losing its sight as a species. Special thanks to @seeingwithsound for the article and pointing me to this topic.
Sometimes, you feel like something is wrong. Most of the time, it’s just a feeling; it doesn’t mean anything. But, every now and then, something is wrong, you really are in danger, you really should be afraid.
Here are some articles on how humans can react to the unconsciously sensed smell of fear in the perspiration of others.
Here’s a paper on the human reaction to putrescine, a chemical associated with death and decay. Even when we don’t consciously notice the smell, we’re instinctively made nervous by its presence.
Here’s a talk by a woman who felt unexplained feelings of dread within her new home. At first, she thought it was a ghost, but eventually she discovered it was something far more deadly.
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To suppose that the eye, with all its inimitable contrivances… could have been formed by natural selection, seems, I freely confess, absurd in the highest possible degree… Yet reason tells me, that if numerous gradations from a perfect and complex eye to one very imperfect and simple, each grade being useful to its possessor, can be shown to exist… and if any variation or modification in the organ be ever useful to an animal under changing conditions of life, then the difficulty of believing that a perfect and complex eye could be formed by natural selection, though insuperable by our imagination, can hardly be considered a real1.
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Charles Darwin (1809–1882)
Darwin included a section in his book, “On the Origin of Species,” called, “Problems With the Theory.” It included the Cambrian explosion, covered in the previous episode, and the development of complex organs like the eye. Today, using things we’ve learned since Darwin’s time, we look at how eyes evolved.
Here are a number of articles with further information.